Honey bees
are arguably our most important commercially available pollinator. They are
responsible for pollinating numerous food plants that make our diets more
exciting and nutritious, including many fruits, vegetables and nuts.

Beekeepers
expect some of their bees to die off from season to season–typically, around 17
percent annually. But in recent years, losses have been more than twice as high[3].

As an
extension apiculturist for the University
of California Cooperative Extension[4], I talk to
many people, from beekeepers and growers to members of the general public,
about honey bees. Most of my audiences are concerned about how honey bee losses
could affect the security of our food supply. While the massive and sudden
colony collapses that occurred a decade ago have abated, honey bees are still
dying at troubling rates. Laboratories like mine are working to understand the
many factors stressing bees and develop strategies for protecting them.

Impacts of
honey bee losses

In 2006
beekeepers in the United States reported that a mysterious affliction,
dubbed Colony Collapse Disorder[5] (CCD),
was causing widespread die-offs of bees. In colonies affected by CCD, adult
workers completely disappeared, although plentiful brood (developing bees) and
the queen remained. Beekeepers found no adult bees in and around the hives, and
noted that pests and bees from neighboring hives did not immediately raid the
affected hives, as might be expected.

Scientists
now agree that CCD was likely caused by a combination of environmental
and biological factors[6], but nothing specific has
been confirmed or proven. CCD is no longer causing large-scale colony death in
North America, but beekeepers all over the United States are still reporting
troubling colony losses – as high as 45 percent annually[7].

While
beekeepers can recoup their losses by making new colonies from existing ones,
it is becoming increasingly costly to keep them going. They are using more
inputs, such as supplemental food and parasite controls, which raises their
operating costs. In turn, they have to charge growers higher prices for
pollinating their crops.

Our
laboratory[14] is evaluating several novel
biopesticides for effectiveness against Varroa and safety to
bees. These products are mostly plant-based, and are designed to be used as
part of an integrated pest management[15] (IPM)
plan. IPM emphasizes prevention and monitoring of pests and using a range of
control methods to minimize negative effects on the environment.

Another
potential strategy is breeding Varroa-resistant bees. Our
research[16] explores biological processes that regulate the honey
bee queen mating process[17]. To breed pathogen- and
parasite-resistant honey bee stock, we often need to use instrumental
(artificial) insemination[18]. We hope
to help improve that process by understanding which seminal fluid proteins from
male honey bees (drones) cause specific post-mating changes in queens, such as
triggering egg-laying or contributing to queen bees' longevity.

Honey bees
also are exposed to viruses, bacterial diseases and fungi[19]. For
example, deformed wing virus (DWV) causes wing deformities that prevent bees
from performing normal work functions such as foraging for food. Viruses have
been implicated as an important factor in honey bee health declines, but we are
just starting to understand how
honey bees' immune systems fight against them[20]. We may be
able to help strengthen bees' immune responses by making diverse foraging
resources, such as a variety of wildflowers, easily accessible.

Pesticide
impacts

Questions
about how pesticides affect honey bee health have spurred passionate debate.
One key issue is whether neonicotinoids, a class of insecticides that affect
insects' nervous systems, are causing widespread bee deaths. The U.S.
Environmental Protection Agency is currently reviewing possible risks to pollinators[21] from
neonicotinoids. Its first results, released earlier this year, found that the
pesticide imidacloprid[22] can
have negative effects when it is present at concentrations above thresholds
that can sometimes be found in certain crops, including citrus and cotton.

There
are many gaps[23] in
our knowledge about neonicotinoids and other types of pesticides. We have
little understanding about the impacts of pesticide combinations and how they
affect developing bees and other pollinators[24]. To fill
some of those gaps, our lab is testing combinations of various agriculturally
important pesticides on adult worker survival and queen development.

Studies
show that when bees have access to optimal nutrition, they are better able
to deal with diseases[25] and pesticides[26]. But intensive farming and
urbanization have reduced the amount of readily available forage that bees need
to thrive. Research labs at UC-Davis[27] and
elsewhere are analyzing what types of flowering plants provide the best
supplemental forage for bees. Growers can support bees by planting these
species near their crops.

Be
bee-friendly

Many people
who are not beekeepers or growers want to know how they can help. One easy step
is to grow forage plants, especially varieties that bloom at different times
during the year. For suggestions, see our Häagen-Dazs
Honey Bee Haven Plant List[28].

Second,
reduce your pesticide use for gardening and landscaping, and follow guidelines
to reduce bee exposure[29]. Finally, you can support
local beekeepers by buying their honey[30].
Ultimately, however, making our society more pollinator-friendly will likely
require some drastic and long-term changes in our environmental and
agricultural practices.

"The master class
has always declared the wars; the subject class has always fought the battles.
The master class has had all to gain and nothing to lose, while the subject
class has had nothing to gain and everything to lose--especially their lives."
Eugene Victor Debs